1. Field of the Invention
The present invention relates to a filter for the separating of solids particles from hot, gaseous or liquid media, especially separating dust particles from hot flue gases in the temperature range of within 120.degree. to 800.degree. C., which consists of a permeable, inherently stable carrier material or substrate which is provided with larger pores; in essence, a support member in which the carrier material is constructed so as to be heat-resistant, and which especially contains constituents of non-corroding materials, such as glass, ceramic, metals or compounds thereof; and in which filter the carrier material can be produced through the intimate, partial bonding of the heat-resistant particles thereof, and wherein the carrier material also possesses a structure or, essentially, a spatial or three-dimensional configuration, which is correlated with the type of utilization and the specified capacity.
It is in general known that for the separation of particles from gaseous or liquid media there are employed filters, and these, in accordance with their field of application, are to be constructed as textile fibers, carbon fiber filters, felt filters, paper filters, plastic filters, and metal or ceramic filters. While the textile, felt, paper and plastic filters are employed within a lower temperature range of up to about 150.degree. C., the metal and ceramic filters can encompass the higher temperature range; for example, such as up to about 800.degree. C., whereby the last-mentioned filters are also adapted to be employed in flue gas areas of heating installations. This is particularly desired inasmuch as, with an increasing reduction in environmentally-contaminating emissions, the filtering of hot gases at temperatures of more than 250.degree. C. constantly increases in the significance thereof, inasmuch as, on the one hand, the high thermal content of the cleaned or purified gases can be readily employed to without having to take any further measures and, on the other hand, these flue gases produce a lower contamination of the environment.
The utilization of the available materials for the filters has shown in regard thereto that glass, ceramic and carbon fibers are susceptible to fracturing as a consequence of being brittle in nature, whereas for metal wires, such as metal webbing or meshes, the interspace between the wires is too large in order to be able to achieve an adequate filtering effect for fine dusts. In addition thereto, in that the utilization of such heat-resistant materials, such as sintered materials, porous, small-pore-sized ceramic materials amongst others, provides relatively little advantage, since the initially good separating action continuously deteriorates, inasmuch as fine dust penetrates into the pores of these materials and which can no longer be loosened therefrom even through special cleaning measures, and thereby finally leads to the blockage of the filter.
With regard to filters intended for use in the so-called high-temperature range, those have been established whose filter elements are primarily constituted from clay or ceramic and which, for purposes of simplicity, are constructed as cylindrical tubes in the shape of filter cartridges. These filter cartridges, which are constructed so as to be open at their ends, are installed between mounting supports in the housing for the filter and fastened therein in such a manner that the medium which is to be filtered will penetrate through the mantle or casing surface of the filter cartridge into the interior thereof and then again exit this interior through an opening at one end of the filter cartridge. This opening of the filter cartridge communicates with a chamber for the filtered medium, and then this medium exits through a discharge connector of the filter. The filter cartridges which are fastened to the mountings are rigidly joined to the latter, and cannot follow or compensate for the loads or stresses caused by the flow of the medium and especially the stresses produced during the cleaning of these cartridges through countercurrent flow, as a result of which it is not possible to be able to prevent fractures, especially at the neck portions of the filter cartridges; referring to German Patent No. 30 17 851.
In order to especially be able to prevent such damages being encountered by the filter cartridges, filter cartridges of this type are swingingly fastened on their mountings. This pendulating fastening of the applicable filter cartridge is facilitated in a manner in that, on the one hand, the mountings which separate the cleaning chamber or space from the filter chamber or space is constructed as an apertured plate, whereby the apertures are so configured that they possess a larger opening cross-section facing towards the cleaning chamber than towards the filter chamber. The filter cartridge, in turn, is equipped with a flange-shaped web at its end towards the cleaning chamber, through which this filter cartridge supports itself on the inwardly drawn bead of the aperture in the mounting. For purposes of a better support of the filter cartridge on this bead, this bead can also be configured as a cup-shaped annular shoulder, and the further cross-section of this aperture beginning from this annular shoulder, increasing towards the filter chamber, is wideningly constructed so as to impart the filter element the necessary space for the swinging moment. The end of the filter element; in essence, the filter cartridge, which is distant from this neck is provided with a bore into which there engages a bolt which is fastened to the mounting. This bolt can be inserted into the bore either with play or without play, whereby with the construction of the bolt in the absence of any play, the latter is supported by means of an elastic sleeve against the filter cartridge. The cup-shaped annular shoulder at the neck of the filter element and the elastic support of the bolt at the opposite end, on the one hand, facilitate the support for the bolt at the opposite end, and on the other hand, the swinging suspension of the filter cartridge on the mountings, so that this cartridge is better protected against damage in comparison with fixedly mounted filter cartridges. However, with regard to this filter it is viewed as being disadvantageous that the applicable filter cartridge is too unsteadily clamped between the mounting which, on the one hand, can lead to sealing problems and thereby to contaminations of the filtered medium, and on the other hand, due to the suspension of the filter cartridges from the cup-shaped annular shoulders, the disassembling of the filter cartridges is rendered more difficult; referring to German Patent No. 35 15 365.